On Fri, Jul 2, 2010 at 10:50 AM, Matthew Wakeling <matthew@xxxxxxxxxxx> wrote: >> On Fri, Jul 2, 2010 at 12:08 AM, Tom Lane <tgl@xxxxxxxxxxxxx> wrote: >>> >>> I'm guessing from tea leaves, but the impression I got from Eliot's >>> description is that he's using plpgsql functions as sort comparators. >>> It's not surprising that that sucks performance-wise compared to having >>> the equivalent logic in C/C++ functions used as comparators on the >>> client side. plpgsql is no speed demon. Best fix might be to code the >>> comparators as C functions on the server side. > > On Fri, 2 Jul 2010, Eliot Gable wrote: >> >> I guess the real question is, is a generic C sorting function my only real >> alternative? > > Sounds to me like you are not really listening. You don't need to code an > entire sorting algorithm in C, as Postgres already has a pretty good one of > those. All you need to do is implement a comparator of some kind. Inserting > C functions into Postgres is pretty easy, especially on the level of > comparators. in recent versions of postgres you rarely if ever even have to do that -- row types are comparable w/o any extra work, as are arrays. If Eliot would just give a little more deal of WHAT he is trying to sort and HOW he is currently doing it, i suspect his problem will be trivially solved :-). merlin -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
